1. Field of the Invention
The present invention generally relates to an electrical connector, and particularly to a low profile electrical connector.
2. The Prior Art
Electrical connectors for input/output port connection are usually provided with a metal shielding shell fitting over and surrounding a mating projection of the connector in order to eliminate electromagnetic interference (EMI). The shielding shell is electrically connected to a circuit board on which the connector is mounted whereby electrostatic charges are discharged. Examples of such shielding shells are disclosed in U.S. Pat. Nos. 4,943,244, 5,066,237, 5,104,326, 5,125,853, 5,218,294, 5,304,069 and 5,591,050. However, the connectors disclosed in these patents have shielding shells positioned between two mating connectors which may not be properly engaged with each other whereby an electrical discontinuity exists when grounding the shielding shell. This adversely affects the protection against EMI provided by the shielding shells.
To overcome the problem of electrical discontinuity, the shielding shell is provided with raised or projecting portion(s) or resilient member(s) which allow a better physical engagement to be established between the shielding shells of two mating connectors. This is known from U.S. Pat. Nos. 4,938,704 and 5,567,169.
However, with the rapid development of computer and telecommunication technology, problems associated with electrostatic discharge (ESD) and cross talk arise. In a connector having multiple rows of pins, the cross talk problem is conventionally resolved by adding a conductive plate or a metal sheet between adjacent rows. When connecting two mating connectors, the conductive plates of the two connectors are brought into contact with each other thereby establishing an electrical engagement therebetween. This technique is taught by U.S. Pat. Nos. 4,824,377, 5,066,240 and 5,567,168. However, conventionally, the conductive plate is provided with a substantially straight mating edge. Thus, the mating edges of the conductive plates of the mating connectors may not be in positive contact engagement with each other due to manufacturing tolerances.
It has also been proposed to provide metal bars on the mating surface of a connector. The metal bars have such a length that allows the bars to contact the mating connector before contacting the pins of the connector. As shown in U.S. Pat. No. 4,179,178 and Taiwan Patent Application Nos. 86204553 and 86206415. This, although providing a better solution, requires a complicated structure of the connector thereby increasing manufacturing cost. Moreover, the connector is not protected from cross talk.
It is thus desirable to have an electrical connector which can overcome the problems of the prior art.